In the molding of synthetic resin materials by injection molding or die-casting processes or in similar techniques utilizing a pair of mold parts which together define a mold cavity, it is common practice to provide each of the mold parts upon a respective mold cavity and to mount the mold carriers movably in a mold-handling assembly.
The purpose of the assembly is to close the mold parts together and hold them in place for a molding operation which can be effected at relatively high pressure, or to spread the mold members apart, thereby enabling a molded object to be removed, the mold part to be cleaned, or the cavity to be inspected.
Especially when relatively large objects are to be fabricated in a mold, the standard method of simply moving the mold parts together or drawing them apart for opening and closing of the mold, is not always satisfactory since the spread of the two mold parts must be quite considerable to allow access to all regions of the mold cavity.
It has been proposed to provide the mold-handling assembly in such manner that upon opening of the mold, the mold carriers can be swung in opposite senses through about 45.degree. so that the opening between the mold parts diverges forwardly with an angle of about 90.degree., i.e. a large mouth is provided for access to the mold. Such a mold-handling unit is described in German patent document (Printed Application--Auslegeschrift) DE-AS No. 26 25 232 (see also U.S. Pat. No. 3,981,671). In this system, each of the mold carriers is swung by respective cylinders about respective pivot axes and still other cylinders are provided for moving the plates or carriers toward or away from one another.
The system of this publication, moreover, has been found to be especially effective for the production of large articles e.g. automotive body components, from thermosetting or other reactive synthetic resin materials. A significant disadvantage is that it requires three distinct drives.
In German patent document (Open Application--Offenlegungsschrift) DE-OS No. 25 44 774, another system for pivoting a mold carrier is described and tilting arrangement also can be found, albeit for different purposes (see also U.S. Pat. No. 3,986,812).